Elasticsearch：6.API简单使用

## 要启用表头，添加 ?v 参数即可
GET /_cat/health?v

## 查看某 API 支持的更多指标（添加 ?help）
GET /_cat/nodes?help

## Elasticsearch Reference
https://www.elastic.co/guide/en/elasticsearch/reference/current/index.html

1.列出所有可用 API

GET /_cat

    =^.^=
    ## 获取所有节点磁盘分配情况
    /_cat/allocation

    ## 获取所有索引的分片信息
    /_cat/shards
    /_cat/shards/{index}

    ## 获取主节点
    /_cat/master

    ## 获取所有节点信息
    /_cat/nodes

    ## 获取当前任务信息
    /_cat/tasks

    ## 获取所有索引指数？
    /_cat/indices
    /_cat/indices/{index}

    ## 
    /_cat/segments
    /_cat/segments/{index}

    ## 获取所有索引数量
    /_cat/count
    /_cat/count/{index}

    ##
    /_cat/recovery
    /_cat/recovery/{index}

    ## 获取健康状态
    /_cat/health

    ## 
    /_cat/pending_tasks
    /_cat/aliases
    /_cat/aliases/{alias}

    ## 获取线程
    /_cat/thread_pool
    /_cat/thread_pool/{thread_pools}

    ## 获取节点已安装插件
    /_cat/plugins

    ## 
    /_cat/fielddata
    /_cat/fielddata/{fields}
    /_cat/nodeattrs
    /_cat/repositories
    /_cat/snapshots/{repository}

    ## 获取模板信息
    /_cat/templates

2.健康检查

GET /_cat/health

    1563348864 07:34:24 ELK-Cluster green 4 3 1140 571 0 0 0 0 - 100.0%

## 要启用表头，添加 ?v 参数即可
GET /_cat/health?v

    epoch      timestamp cluster     status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
    1563348910 07:35:10  ELK-Cluster green           4         3   1140 571    0    0        0             0                  -                100.0%

3.集群内节点统计

GET /_cat/nodes?v

    ip            heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
    192.168.50.14           45          99  18    1.46    2.49     2.81 mdi       *      elk-01
    192.168.50.17           40          90   3    0.06    0.14     0.11 -         -      kibana
    192.168.50.16           49          99  10    1.61    2.33     2.51 mdi       -      elk-03
    192.168.50.15           71          99  10    1.04    1.62     2.38 mdi       -      elk-02

## 查看指定信息
GET /_cat/nodes?v&h=ip,port,heapPercent,heapMax

    ip            port heapPercent heapMax
    192.168.50.14 9300          64   7.8gb
    192.168.50.17 9300          42   3.8gb
    192.168.50.16 9300          63   7.8gb
    192.168.50.15 9300          48   7.8gb

4.通过添加 ?bytes=b 关闭人类可读的数字格式化

curl '192.168.50.17:9200/_cat/indices?bytes=b' | sort -rnk8 | grep -v marvel
GET /_cat/indices?bytes=b

5.获取集群健康状态

GET _cluster/health

    {
      "cluster_name" : "ELK-Cluster",
      "status" : "green",
      "timed_out" : false,
      "number_of_nodes" : 4,
      "number_of_data_nodes" : 3,
      "active_primary_shards" : 571,
      "active_shards" : 1140,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0,
      "delayed_unassigned_shards" : 0,
      "number_of_pending_tasks" : 0,
      "number_of_in_flight_fetch" : 0,
      "task_max_waiting_in_queue_millis" : 0,
      "active_shards_percent_as_number" : 100.0
    }